The present invention relates to a videodisk player for playing not only a constant angular velocity (CAV) disk whose rotational angular velocity is constant but also a constant linear velocity (CLV) disk whose rotational linear velocity is constant.
There are two types of videodisks. The first type is the CAV disk on which are stored video signals having a fixed number of fields (for instance, two or four fields) per track. The disk is rotated at a given fixed angular velocity. The second type of disk is the CLV disk on which the number of fields per track increases as the diameter increases. For instance, there are typically two fields on the innermost track but about six fields on the outermost track. A CLV disk is rotated at a variable angular velocity so as to produce a given fixed linear tracking velocity.
In the case of the CAV disk, the time base servo will be substantially free from disturbance even if the pickup is made to jump because the vertical synchronizing signals are arranged along a given radial line. Therefore, it is relatively easy to use a CAV disk for both normal playback and also special playback, such as slow, still and fast playback. On the hand, for a CLV disk, the time base servo will be disturbed to a large extent if the pickup is made to jump because the vertical synchronizing signals are not located on a given radial line of the CLV disk, and this results in relative difficulty in accomplishing special playback effects such as slow, still and fast playback. Special operations such as slow, still and fast playback for a CLV disk are possible, however, using techniques such as disclosed in Japanese Laid-Open Pat. Appln. No. 58-98881.
Although such a conventional disk player is capable of providing color images with a stable time base servo, there is a drawback in that the reproduced images are uncomfortable to look at as the vertical synchronizing signals are discontinuous.